4l80e manual valve body - downshifted unexpectively
05-26-2010, 05:39 AM
#1
Staging Lane
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4l80e manual valve body - downshifted unexpectively I have a 4l80e stage 3 transgo and it's pretty new but after my motor went i was driving across town and then noticed in 2nd gear i gave it some gas to go up the hill 280hp worth and the car immediately slipped into 1st gear then as i lifted went back to 2nd really fast. This happened a few times. I called my transmission builder about it and he was kind of clueless.
Later i tried to re-replicate the occurance with no luck. Perhaps it was too hot? Perhaps the cable was too tight and the torque of the engine and transmission made the car skip down a gear?
This transmission has about 550 miles on it.
Later i tried to re-replicate the occurance with no luck. Perhaps it was too hot? Perhaps the cable was too tight and the torque of the engine and transmission made the car skip down a gear?
This transmission has about 550 miles on it.
05-26-2010, 07:20 AM
#3
I've heard rumors of delayed or slipping WOT shifts when fluid is hot with those transgo 3s. If the car was shifting fine previously and the shifter is operating correctly still, I'd think the cable is fine. Do you have the vacuum modulator hooked up? Maybe an issue with that along with the fluid being hot and line pressure being too low? Have you checked your fluid level? I had a similar issue with my last car with a 4L60E in it. Uphill on the gas or hard acceleration and it didn't want to find 3rd gear and would just neutral out and felt like the tranny was slipping big time. Put 1.5qts more fluid in it and it was fine after.
05-26-2010, 01:52 PM
#4
I've heard rumors of delayed or slipping WOT shifts when fluid is hot with those transgo 3s. If the car was shifting fine previously and the shifter is operating correctly still, I'd think the cable is fine. Do you have the vacuum modulator hooked up? Maybe an issue with that along with the fluid being hot and line pressure being too low? Have you checked your fluid level? I had a similar issue with my last car with a 4L60E in it. Uphill on the gas or hard acceleration and it didn't want to find 3rd gear and would just neutral out and felt like the tranny was slipping big time. Put 1.5qts more fluid in it and it was fine after.
05-26-2010, 07:09 PM
#5
Staging Lane
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Hmm sounds like it was hot. I better get my pressure gauge in the cockpit. I got the line all ready just need to find a good line pressure gauge with a light.
05-26-2010, 10:05 PM
#6
Staging Lane
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I've heard rumors of delayed or slipping WOT shifts when fluid is hot with those transgo 3s. If the car was shifting fine previously and the shifter is operating correctly still, I'd think the cable is fine. Do you have the vacuum modulator hooked up? Maybe an issue with that along with the fluid being hot and line pressure being too low? Have you checked your fluid level? I had a similar issue with my last car with a 4L60E in it. Uphill on the gas or hard acceleration and it didn't want to find 3rd gear and would just neutral out and felt like the tranny was slipping big time. Put 1.5qts more fluid in it and it was fine after.
yes i have teh vacuum modulator.
05-30-2010, 05:39 AM
#7
Staging Lane
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Go figure readjust the gear linkage which was semi angled weird potentially. Just to hook up a line pressure gauge and find out my in gear line pressure is 130 instead of the 215 recommended. Reverse was 195 when it should be around 300! 
500 miles on it with this low line pressue issue before. Something is going funky in this transmission.
*sigh*
500 miles on it with this low line pressue issue before. Something is going funky in this transmission.*sigh*
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05-30-2010, 08:21 AM
#8
How exactly were you testing line pressure? Vac line connected? At idle? Wot?
I personally have used this kit a bunch of times and have never had the complaints that guys talk about. Then again the average doityourselfer might not do things the same way I do. I have seen plenty of home installs done and fail shortly after the install. I guess that is half of the problem. Some guys just should not mess with this stuff because it only costs time and money in the end for something that does not work.
I personally have used this kit a bunch of times and have never had the complaints that guys talk about. Then again the average doityourselfer might not do things the same way I do. I have seen plenty of home installs done and fail shortly after the install. I guess that is half of the problem. Some guys just should not mess with this stuff because it only costs time and money in the end for something that does not work.
05-31-2010, 05:27 AM
#9
Staging Lane
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How exactly were you testing line pressure? Vac line connected? At idle? Wot?
I personally have used this kit a bunch of times and have never had the complaints that guys talk about. Then again the average doityourselfer might not do things the same way I do. I have seen plenty of home installs done and fail shortly after the install. I guess that is half of the problem. Some guys just should not mess with this stuff because it only costs time and money in the end for something that does not work.
I personally have used this kit a bunch of times and have never had the complaints that guys talk about. Then again the average doityourselfer might not do things the same way I do. I have seen plenty of home installs done and fail shortly after the install. I guess that is half of the problem. Some guys just should not mess with this stuff because it only costs time and money in the end for something that does not work.
At idle and in gear and loading it up it makes the same line pressure approximately. I haven't done WOT.
I was testing line pressure iwth a 5 foot line connected to a gauge in the cockpit.
05-31-2010, 02:32 PM
#10
How exactly were you testing line pressure? Vac line connected? At idle? Wot?
I personally have used this kit a bunch of times and have never had the complaints that guys talk about. Then again the average doityourselfer might not do things the same way I do. I have seen plenty of home installs done and fail shortly after the install. I guess that is half of the problem. Some guys just should not mess with this stuff because it only costs time and money in the end for something that does not work.
I personally have used this kit a bunch of times and have never had the complaints that guys talk about. Then again the average doityourselfer might not do things the same way I do. I have seen plenty of home installs done and fail shortly after the install. I guess that is half of the problem. Some guys just should not mess with this stuff because it only costs time and money in the end for something that does not work.
I've used the kit dozens of times as well and have seen on SOME units strange issues.
The biggest complaint is a delayed 2-3 shift. It is firm but takes some time from the time you move the shifter until it shifts.
I have "fixed" this issue with some changes I do.
On a couple of transmissions I have seen a no WOT 1-2 shift when the trans is up to temp.
It just doesn't shift, but let off the throttle and it will make the shift.
This is a fluid pressure issue because the 1-2 shift valve can't exhaust to upshift.
It is happening between the VB and the "sandwich plate" under the pressure manifold switch. It needs to be o-ringed on the VB side of the plate.
The problems that do show up are worse as the pressures get higher.
TransGo has changed the -3 kit recently, the new kits are shipping now, they have a seperator plate similar to the -2 kit.
I also have a transbrake that works with the TransGo -3 kit, but I quit using them after I developed my new transbrake that works with automatic or manual 4L80Es.
I've got a box full of the the TransGo style full manual 4L80E kits with or without transbrakes if you know anybody that wants them. They are setup for fixed line pressure (no modulator) but are simpler to install (pre-made seperator plates).
05-31-2010, 06:19 PM
#11
Staging Lane
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Vince,
I've used the kit dozens of times as well and have seen on SOME units strange issues.
The biggest complaint is a delayed 2-3 shift. It is firm but takes some time from the time you move the shifter until it shifts.
I have "fixed" this issue with some changes I do.
On a couple of transmissions I have seen a no WOT 1-2 shift when the trans is up to temp.
It just doesn't shift, but let off the throttle and it will make the shift.
This is a fluid pressure issue because the 1-2 shift valve can't exhaust to upshift.
It is happening between the VB and the "sandwich plate" under the pressure manifold switch. It needs to be o-ringed on the VB side of the plate.
The problems that do show up are worse as the pressures get higher.
TransGo has changed the -3 kit recently, the new kits are shipping now, they have a seperator plate similar to the -2 kit.
I also have a transbrake that works with the TransGo -3 kit, but I quit using them after I developed my new transbrake that works with automatic or manual 4L80Es.
I've got a box full of the the TransGo style full manual 4L80E kits with or without transbrakes if you know anybody that wants them. They are setup for fixed line pressure (no modulator) but are simpler to install (pre-made seperator plates).
I've used the kit dozens of times as well and have seen on SOME units strange issues.
The biggest complaint is a delayed 2-3 shift. It is firm but takes some time from the time you move the shifter until it shifts.
I have "fixed" this issue with some changes I do.
On a couple of transmissions I have seen a no WOT 1-2 shift when the trans is up to temp.
It just doesn't shift, but let off the throttle and it will make the shift.
This is a fluid pressure issue because the 1-2 shift valve can't exhaust to upshift.
It is happening between the VB and the "sandwich plate" under the pressure manifold switch. It needs to be o-ringed on the VB side of the plate.
The problems that do show up are worse as the pressures get higher.
TransGo has changed the -3 kit recently, the new kits are shipping now, they have a seperator plate similar to the -2 kit.
I also have a transbrake that works with the TransGo -3 kit, but I quit using them after I developed my new transbrake that works with automatic or manual 4L80Es.
I've got a box full of the the TransGo style full manual 4L80E kits with or without transbrakes if you know anybody that wants them. They are setup for fixed line pressure (no modulator) but are simpler to install (pre-made seperator plates).
06-02-2010, 02:25 PM
#12
Vince,
I've used the kit dozens of times as well and have seen on SOME units strange issues.
The biggest complaint is a delayed 2-3 shift. It is firm but takes some time from the time you move the shifter until it shifts.
I have "fixed" this issue with some changes I do.
On a couple of transmissions I have seen a no WOT 1-2 shift when the trans is up to temp.
It just doesn't shift, but let off the throttle and it will make the shift.
This is a fluid pressure issue because the 1-2 shift valve can't exhaust to upshift.
It is happening between the VB and the "sandwich plate" under the pressure manifold switch. It needs to be o-ringed on the VB side of the plate.
The problems that do show up are worse as the pressures get higher.
TransGo has changed the -3 kit recently, the new kits are shipping now, they have a seperator plate similar to the -2 kit.
I also have a transbrake that works with the TransGo -3 kit, but I quit using them after I developed my new transbrake that works with automatic or manual 4L80Es.
I've got a box full of the the TransGo style full manual 4L80E kits with or without transbrakes if you know anybody that wants them. They are setup for fixed line pressure (no modulator) but are simpler to install (pre-made seperator plates).
I've used the kit dozens of times as well and have seen on SOME units strange issues.
The biggest complaint is a delayed 2-3 shift. It is firm but takes some time from the time you move the shifter until it shifts.
I have "fixed" this issue with some changes I do.
On a couple of transmissions I have seen a no WOT 1-2 shift when the trans is up to temp.
It just doesn't shift, but let off the throttle and it will make the shift.
This is a fluid pressure issue because the 1-2 shift valve can't exhaust to upshift.
It is happening between the VB and the "sandwich plate" under the pressure manifold switch. It needs to be o-ringed on the VB side of the plate.
The problems that do show up are worse as the pressures get higher.
TransGo has changed the -3 kit recently, the new kits are shipping now, they have a seperator plate similar to the -2 kit.
I also have a transbrake that works with the TransGo -3 kit, but I quit using them after I developed my new transbrake that works with automatic or manual 4L80Es.
I've got a box full of the the TransGo style full manual 4L80E kits with or without transbrakes if you know anybody that wants them. They are setup for fixed line pressure (no modulator) but are simpler to install (pre-made seperator plates).
Jakeshoe, You fixed mine. My 4l80 FMVB with the Transgo-3 ,and it would not shift from first to second after it got hot, but now it works perfectly.Thanks for the fix. And very nice transbrake also.
